King Street Carhouse
For over three decades, this was the site of the King Street Carhouse, once the largest streetcar facility in the city. The first railway stables on this site were constructed in 1887 by the Toronto Street Railway (TSR), which used horse-driven streetcars. In 1891, the TSR was succeeded by the Toronto Railway Company (TRC), the city's first electric streetcar operator. The original facility was expanded several times to handle the growing fleet, and by 1904, more than half of the company's 765 cars and trailers were run out of these buildings.
In March 1912, a fire damaged the carhouse and destroyed 145 streetcars. Then, in 1916, a second fire destroyed the building completely, as well as 163 cars. Operations shifted to the Russell Carhouse on Queen Street East. In 1921, the TRC's franchise expired. The Toronto Transportation Commission amalgamated it with three other street rail companies, eliminating the need for riders to pay up to nine fares to cross the city.
Plaque via Alan L. Brown's site Toronto Plaques. Full page here.